Cyclodextrin based bone regenerative inclusion complex for resveratrol in postmenopausal osteoporosis

Recent preclinical studies have shown that resveratrol (RSV), is a promising remedy for osteoporosis owing to its estrogenic, anti-inflammatory, and antioxidant properties. However, RSV has met limited success due to its poor oral bioavailability and inefficient systemic delivery. In this study, we prepared the inclusion complex of RSV with sulfo-butyl ether β-cyclodextrin (SBE-β-CD) to enhance the aqueous solubility of RSV. The in-silico docking studies and Physico-chemical characterization assays were performed to understand the interaction of RSV inside the SBE-β-CD cavity. The in vivo safety assessment of RSV-SBE-β-CD inclusion complex (R-CDIC) was performed in healthy Wistar rats. The efficacy of the inclusion complex against postmenopausal osteoporosis was further investigated in ovariectomized (OVX) rat model. The alteration in the bone micro-architectural structure was evaluated by microcomputed tomographic scanning, serum biochemical estimations, biomechanical strength and histopathological investigation. Administration of RSV-SBE-β-CD inclusion complex was found to be safe and significantly improved micro-architectural deterioration induced by estrogen withdrawal. Results of bone morphometry and biomechanics study further emboldened the efficacy claim of the RSV-SBE-β-CD complex. Thus, the present study demonstrated the efficacy of the RSV-SBE-β-CD inclusion complex for treating osteolytic degradation in osteoporosis.

Antitumor activity of a novel dual functional podophyllotoxin derivative involved PI3K/AKT/mTOR pathway

The progression of cancer through local expansion and metastasis is well recognized, but preventing these characteristic cancer processes is challenging. To this end, a new strategy is required. In this study, we presented a novel dual functional podophyllotoxin derivative, 2-pyridinealdehyde hydrazone dithiocarbamate S-propionate podophyllotoxin ester (PtoxPdp), which inhibited both matrix metalloproteinases and Topoisomerase II. This new podophyllotoxin derivative exhibited significant anti-proliferative, anti-metastatic that correlated with the downregulation of matrix metalloproteinase. In a xenograft animal local expansion model, PtoxPdp was superior to etoposide in tumor repression. A preliminary mechanistic study revealed that PtoxPdp induced apoptosis and autophagy via the PI3K/AKT/mTOR pathway. Furthermore, PtoxPdp could also inhibit epithelial-mesenchymal transition, which was achieved by downregulating both PI3K/AKT/mTOR and NF-κB/Snail pathways. Taken together, our results reveal that PtoxPdp is a promising antitumor drug candidate.

Potential role of the HOXD8 transcription factor in cisplatin resistance and tumour metastasis in advanced epithelial ovarian cancer

Few studies have examined the potential transcription factor (TF) simultaneously associated with cisplatin resistance and metastasis in ovarian cancer. To assess a related mechanism, a 345-channel protein/DNA array and transcriptional activity ELISA were performed to compare the TF activities in the cisplatin-sensitive SKOV3 and cisplatin-resistant SKOV3-DDP cells and in HO-8910 and the homologous highly metastatic HO-8910PM cells. In SKOV3-DDP vs. SKOV3 cells, 43 TFs were up-regulated, while 31 were down-regulated. In HO-8910PM vs. HO-8910 cells, 13 TFs were up-regulated, while 18 were down-regulated. In these two models, 4 TFs (HOXD8(1), HOXD8(2), RB, RFX1/2/3) were simultaneously up-regulated, and 9 TFs (SRE, FKHR, Angiotensinogen ANG-IRE, Pax2, CD28RC/NF-IL2B, HLF, CPE, CBFB and c-Ets-1) were down-regulated. HOXD8 mRNA and protein expression levels measured by reverse transcription polymerase chain reaction and ELISA, respectively, were significantly higher in SKOV3-DDP and HO-8910PM than in their corresponding cell lines (both p < 0.05). In 52 cases of different ovarian disease, the patients with recurrent and cisplatin-resistant ovarian cancer had higher expression levels of HOXD8 than patients with primary malignant tumours (p = 0.018, p = 0.001) or benign tumours (p = 0.001, p < 0.001). Taken together, these results suggest that HOXD8 is potentially associated with both cisplatin resistance and metastasis in advanced ovarian cancer.

The antitumor mechanism of di-2-pyridylketone 2-pyridine carboxylic acid hydrazone and its copper complex in ROS generation and topoisomerase inhibition, and hydrazone involvement in oxygen-catalytic iron mobilization

Iron depletion and stimulation of iron-dependent free radical damage is a rapidly developing field for chelation therapy, but the iron mobilization from ferritin by chelators has received less attention. In this study, the di-2-pyridylketone 2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex was prepared and characterized by NMR and MS spectra. The proliferation inhibition assay showed that both DPPCAH and its copper complex exhibited selectively proliferation inhibition for HepG2 (IC50, 4.6 ± 0.2 µM for DPPACH and 1.3 ± 0.2 µM for its copper complex), but less inhibition for HCT-116 cell line (IC50, >100 µM for DPPACH and 7.8 ± 0.4 µM for its copper complex). The mechanistic studies revealed that DPPACH could remove iron from ferritin in a oxygen-catalytic manner, and contributed to redox activity of labile iron pool (LIP), that is less reported for the chelators that possess significant biological activity. The reactive oxygen species (ROS) generation and DNA cleavage assay in vitro and in vivo showed that both DPPACH-Fe(II) and DPPACH-Cu were redox-active species, indicating that ROS may mediate their antitumor activity. Further study revealed that both DPPACH and its copper complex displayed certain degree of inhibition of type II topoisomerase (Top) which contributed to their antitumor activity. Thus, the mechanism that iron mobilization by DPPACH from ferritin contributed to LIP was proposed, and both DPPACH and its copper complex were involved in ROS generation and Top II inhibition for their antitumor activities.

Ciprofloxacin containing Mannich base and its copper complex induce antitumor activity via different mechanism of action

The Mannich base containing ciprofloxacin and kojic acid structural units was prepared and evaluated in antitumor activity. The enhancement in antitumor activity was observed both from the Mannich base (IC(50): 103.3±5.0 µM for HepG2, 87.9±8.0 µM for HCT-116 cell) and its copper complex (IC(50): 11.5±1.8 µM for HepG2, 44.4±2.5 µM for HCT-116 cell) compared to the ciprofloxacin and kojic acid. The mechanistic studies via RT-PCR, cell cycle analysis, mitochondrial membrane potential measurement, inhibition of topoisomerase and molecular docking indicated that there is a different molecular mechanism between the Mannich base and its copper complex. The cytotoxicity of the Mannich base was involved in apoptosis, cell cycle arrest, depolarization of mitochondrial membrane and weaker topoisomerase II inhibition, but the copper complex exerted its cytotoxicity mainly through dual topoisomerase inhibition, especially stabilizing the intermediate of cleavage DNA-topoisomerase complex.

The cytotoxicity of benzaldehyde nitrogen mustard-2-pyridine carboxylic acid hydrazone being involved in topoisomerase IIα inhibition

The antitumor property of iron chelators and aromatic nitrogen mustard derivatives has been well documented. Combination of the two pharmacophores in one molecule in drug designation is worth to be explored. We reported previously the syntheses and preliminary cytotoxicity evaluation of benzaldehyde nitrogen mustard pyridine carboxyl acid hydrazones (BNMPH) as extended study, more tumor cell lines (IC₅₀ for HepG2: 26.1 ± 3.5 μM , HCT-116: 57.5 ± 5.3 μM, K562: 48.2 ± 4.0 μM, and PC-12: 19.4 ± 2.2 μM) were used to investigate its cytotoxicity and potential mechanism. In vitro experimental data showed that the BNMPH chelating Fe²⁺ caused a large number of ROS formations which led to DNA cleavage, and this was further supported by comet assay, implying that ROS might be involved in the cytotoxicity of BNMPH. The ROS induced changes of apoptosis related genes, but the TFR1 and NDRG1 metastatic genes were not obviously regulated, prompting that BNMPH might not be able to deprive Fe²⁺ of ribonucleotide reductase. The BNMPH induced S phase arrest was different from that of iron chelators (G1) and alkylating agents (G2). BNMPH also exhibited its inhibition of human topoisomerase IIα. Those revealed that the cytotoxic mechanism of the BNMPH could stem from both the topoisomerase II inhibition, ROS generation and DNA alkylation.